1st year is hard as although the work is not actually too bad you are just getting into the swing of things and learning to work independently without someone always watching over you. You are also just learning to live independently and (slowly) learning how to be and adult! It can be a bit overwhelming for some, but you are well supported.
2nd year is probably the hardest year as you are cramming a year's worth of content into 2 terms, in order to make way for 4 terms of intercalation.
3rd year (plus end of 2nd year) is intercalation and is much lower contact time. Hence, it is easier to do less work and is generally viewed as an easy year if you want it to be.
4th year is great as its your first clinical year and finally what you signed up for as a med student. Exam pressure is also much lower than any previous year
5th year you get a set of exams every 8 weeks for 48 weeks, although that's probably not actually as bad as it sounds as you just get numb to it after a while.
6th year is split in half - first half is preparing for finals which can be quite stressful (even though actual pass rates are ~99%, higher than all 5th year exams!). Second half is fantastic - a stress free no-requirements elective for 11 weeks, some optional placements based on your intersts with the aim being to find out about areas of interest and build CV a bit, and some preparing for placement rotations.
Students can still be biased